Countess at work for 50th birthday

The Countess of Wessex has been photographed looking relaxed and smiling in a special portrait image released to mark her 50th birthday.

The milestone has been commemorated with the simple black and white picture showing Sophie seated and wearing a white shirt.

The Countess will celebrate her birthday on Tuesday but will not be taking the day off as she has two engagements in London with her husband the Earl.

The royal couple will meet staff and supporters from Tomorrow's People, a national employment charity that has Sophie as its patron and which works in local communities to help disadvantaged adults and young people get and keep a job.

Later they will visit the London School of Hygiene and Tropical Medicine to see demonstrations of the Avoidable Blindness Programme supported by the Queen Elizabeth Diamond Jubilee Trust.

The Countess is passionate about eradicating avoidable blindness and is patron of Vision 2020: The Right to Sight and a global ambassador for the International Agency for the Prevention of Blindness,

Sophie will be officially named as the new vice-patron of the Trust which supports those in need across the Commonwealth and is chaired by former prime minister Sir John Major.

The Countess was born Sophie Rhys-Jones and like the Duchess of Cambridge, hails from a middle-class background.

Her father was a former car salesman and she was brought up in a Kent village near Tunbridge Wells.

She has been a member of the Royal Family for more than 15 years after marrying the Earl at St George's Chapel in Windsor on June 19 1999.

They were brought together by a mutual passion for the ancient sport of real tennis and romance blossomed between Edward, 50, and Sophie, 49, a former public relations woman, who once worked for Capital Radio.

Problems arose when Sophie tried to combine her life as a royal with her professional career.

She was caught in a Sunday tabloid sting and accused of trying to use her status to promote her business.

Sophie and Edward later stepped down from their individual careers to become full-time royals.

They now work supporting a range of charities and good causes and bringing up their two children, Lady Louise Windsor, aged 11, and seven-year-old Viscount Severn.